Three cases of avian influenza, or bird flu, in humans were confirmed Saturday by Dr. Trinh Quan Huan, head of Vietnam´s preventive medicine department. The disease reportedly is showing up mostly in the southern regions of the country where poultry outbreaks have been recurring.

China´s Yunnan province, which shares a 1,200-kilometer border with Vietnam, is taking emergency steps to prevent the transmission of the virus to its population, according to press reports. Poultry vaccinations are being urged and disinfecting stations are being set up along the border.

Teenager in Critical Condition

Laboratory tests conducted in Ho Chi Minh City identified a strain of the H5N1 virus that is lethal to human beings. The three cases were identified between December 16 and January 7.

The most recent victim is a 16-year old girl in Tay Ninh province. She is hospitalized in critical condition, according to the World Health Organization (WHO).

The earlier cases involved two boys, a 7-year old in Dong Thap province and a 10-year old in Tra Vinh province. Both of those children have died.

More Active in Cool Weather

Close contacts of these cases are being monitored for any signs of illness. Health authorities in Viet Nam, supported by WHO staff, have undertaken several measures to strengthen case detection.

Avian influenza viruses become more active when temperatures turn cooler. Activities associated with the approach of the Lunar New Year festivities in early February may increase the risk of further human cases.

"The epidemic of highly pathogenic avian influenza caused by H5N1, which began in mid-December 2003 in the Republic of Korea and is now being seen in other Asian countries ... is of particular public health concern," says a fact sheet on avian influenza on WHO´s Web site.

Influenza Pandemic Expected

"H5N1 variants demonstrated a capacity to directly infect humans in 1997, and have done so again in Viet Nam in January 2004," the statement continues. The fact sheet does not mention the three most recent cases, however.

"The spread of infection in birds increases the opportunities for direct infection of humans," WHO explains. "If more humans become infected over time, the likelihood also increases that humans, if concurrently infected with human and avian influenza strains, could serve as the ´mixing vessel´ for the emergence of a novel subtype with sufficient human genes to be easily transmitted from person to person. Such an event would mark the start of an influenza pandemic."

As the latest news indicates, more humans have, in fact, become infected. While the emergence of a "novel subtype" has not yet been confirmed, a suspected case of human-to-human transmission occurred last year in Thailand, when a 26-year-old woman died after apparently getting the virus from her 11-year-old daughter.

"Even in the best case scenarios of the next pandemic, 2 to 7 million people would die and tens of millions would require medical attention," says WHO in a statement. "If the next pandemic virus is a very virulent strain, deaths could be dramatically higher."

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Southwest China´s Yunnan Province, which borders Vietnam, has taken a series of emergency measures to prevent bird flu in Vietnam from spreading into China, sources with the local government said Saturday.

    All major transportation lines, poultry farms, regions on the Sino-Vietnam border and places which were hit by bird flu outbreak early last year have been urged to inject vaccine on poultry, the sources said.

    The provincial government has urged local agricultural, health,import and export quarantine, public security, quality inspection departments and customs officers to work together to monitor possible spread of bird flu and distribution of poultry and egg products in Yunnan. Anyone who causes the spread of bird flu as result of dereliction of duty will be punished harshly, the sources said.

    Meanwhile, the local animal husbandry department has set up a 30-km-wide "immune protection zone" in the border area neighboring Vietnam and set up disinfecting stations at the frontier passages and border ports to make thorough check and disinfect all vehicles and personnel passing by.

    A three-layer report system, involving participation of households, villages and township, has been built in rural areas of Yunnan. Any outbreak of bird flu should be reported to higher authority within 24 hours.

    Yunnan shares a 1,200-kilometer-long border with Vietnam, wherepeople of 13 ethnic groups live across border and there are nearly100 marketplaces for cross border trade.

    The relapse of bird flu has been seen in 11 localities of Vietnam since December last year. An 18-year-old girl from Vietnam´s southern region has just been hospitalized for being suspected of having contracted virus H5N1, raising the number of confirmed and suspected cases of bird flu to five.